The so-called '3 nines' result marks the successful completion of the start-to-finish proof of concept for the processes involved in the purification chain.

It said the successful operation of the technology at pre-commercial continuous scale has directly extracted lithium from Arkansas brine and produced a "purified, concentrated intermediate product (LiCl solution)" and converted it to a "better than battery" quality final product.

"The culmination of the proof-of-concept was to convert and crystallise the LiCl solution produced by the company's first-of-its-kind direct lithium extraction (DLE) demonstration plant," the company said.

The LiCl solution from Arkansas was then concentrated further with reverse osmosis technology, and then converted at its SiFT pilot plant in Richmond, British Columbia, Canada.

With the carbonate recrystallised with the SiFT technology, the high-purity lithium carbonate was subsequently sent for third-party analysis.

The conversion of the lithium chloride to carbonate done with a conventional process is still ongoing using a third-party vendor.

"Standard Lithium continues to operate both the LiSTR DLE plant in Arkansas and the SiFT pilot plant in BC…to gather additional operational data and refine design parameters to allow for future commercial scaling of the technologies," the company said.

Once the restrictions of the coronavirus pandemic are lifted or eased, Standard Lithium will relocate the SiFT plant from Richmond to Arkansas and integrate it into the existing plant.

President and COO Andy Robinson called the results of the proof-of-concept an important milestone for the company.

"We've managed to demonstrate the first of its kind continuous extraction of lithium from Smackover brine and we've converted it into better than battery quality material. Not only that, but we've done it at a large scale, which now allows us to keep on working towards commercialisation," he said.